HIRDLS is a multi-channel limb-viewing infrared
(IR) radiometer for high resolution monitoring of upper tropospheric,
statospheric, and mesospheric temperature, trace chemicals, and geopotential
height gradients. These are the key elements that are needed to understand
the chemistry and dynamics of those regions, including the roles of planetary
and gravity waves in transporting and mixing radiatively and chemically active
species that are important to climate change. The instrument has a better
vertical resolution than previous limb sounders, because of its smaller field
of view, and the horizontal spacing between the profiles is much closer because
the instrument is able to scan azimuthaly.